$ { \left[\begin{array}{r}{1} \\ {0} \\ {-1}\end{array}\right]+\left[\begin{array}{r}{-2} \\ {4} \\ {-1}\end{array}\right] = {?} } $
Solution: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{r}{1}+{-2} \\ {0}+{4} \\ {-1}+{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{-1} \\ {4} \\ {-2}\end{array}\right]}$